Wonder where we got the sexagesimal system? 60 seconds seems awful unwieldy in our world of base 10.
It's the Sumerians.
Someone on Reddit's ELI5 forum asked:
"Why do we hit a limit of 60 for seconds and minutes, but then decimal for hours and milliseconds?"
and the answer is very cool:

If the Reddit thread doesn't explain it as you like, try Wikipedia.